Drought and downpours in Santiago

Melissa writes*

From shortages to excesses, water presents unique challenges in the Santiago Metropolitan Region (MR) of Chile where nearly half of the country’s population resides. Two seemingly contrasting problems, droughts and downpours, are at fault.

Urban and rural communities in the MR face a future in which the growing demand for potable water contrasts with a decline in water resources (Nunez, 2019). Extreme heat waves combined with precipitation rates that have declined by 20 to 30% in the past two decades, have led to chronic water shortages. Right now, the MR is suffering from the driest decade in recorded history.

The above factors clash with an already existing allocation problem. An estimated 20 aquifers are over-allocated in the MR, signifying that the rights to pump groundwater exceed the availability of water resources. Diminishing groundwater supplies are leaving the country’s agricultural economy and rural communities more and more vulnerable to drought (Becerra et al., 2019).

Furthermore, the Maipo watershed is in a “critical state of conservation”, with less than 1% under formal protection. As a key player in the regional economy, the basin supplies water for mining and energy production, irrigates more than 90% of the basin’s agricultural area and supplies 80% of Santiago’s drinking water.

Unfortunately, the increasing temperatures and the decreasing rainfall make the waters of the Maipo Basin among the most vulnerable resources to climate change. By 2070, the basin is projected to suffer a 40% reduction in water flow due to decreased precipitation and glacial retreat. Precipitation in the MR’s Andes mountains has decreased by 3 cm per 10 years, according to the Chilean Antarctic Institute. This has led to 8.54 to 15.14 gigatonnes of glacial retreat, an amount which would have been “enough to meet all of Chile’s water needs for the next 14 years”.

Ironically, as the country faces a future of water scarcity, the risk of flooding in Santiago is expected to increase each year mainly due to urbanisation, loss of vegetation and above-average temperatures (Becerra, 2019). Floods not only cause major economic losses, they also disrupt water supply, compromise water quality, increase health risks, and significantly damage infrastructure (Kerstin Krellenberg et al., 2013).

When compared with the averages from 1912 to 1999, the MR has seen a 22% increase in floods and almost six times more landslides per year between 2000 and 2017. To provide an example, in 2017, a mere 5 mm of rain in Santiago caused calamitous floods and landslides that cut off water to more than six million people. Technically, 5 mm is considered a moderate shower, so why were the floods so severe? First, fires that had been raging in the MR in previous weeks caused severe deforestation, eliminating large amounts of trees that help retain water and reduce erosion. Second, the parched soil from the prolonged drought had lost its absorptive capacity and even became hydrophobic (water-repelling) (Herrera, 2019).

These pressing water problems are likely to become even more complex when paired with population growth, urbanisation and climate change (Becerra et al., 2019).

Bottom Line: As Santiago prepares itself for a future with more people, less water, and more flooding, it will become increasingly vital for water users, legislators and regulators to work together to manage water resources in a sustainable way.


* Please help my Water Scarcity students by commenting on unclear analysis, alternative perspectives, better data sources, or maybe just saying something nice 🙂

Author: David Zetland

I'm a political-economist from California who now lives in Amsterdam.

4 thoughts on “Drought and downpours in Santiago”

  1. Hi Melissa, I really enjoyed reading your blogpost and learning about how much of a paradox the situation currently is in Santiago. I guess it really highlights how climate change causes such huge fluctuations in weather patterns and how the effects of rainfall and high temperatures can both can both interlink with one another to effect water levels. You would almost think that with such high temperatures that rain would be exactly what the region needs but the fact that it ends up being a hindrance seems to make the situation that bit more complicated. What also seems to make it difficult to solve is that the two problems back each other up, through increased temperature drying out land making flooding more likely and then the subsequent floods impact water supply and quality. In a way, the situation comes across as a self sustaining cycle.

    I just had a some questions in regard to water allocation and protection 🙂 First of all I wasn’t quite sure what was meant by less than 1% of the Maipo watershed being under formal protection and was wondering if you could maybe provide some more information about this? Furthermore, had some questions about water over-allocation. Is there a certain group or industry who are benefitting most from water allocation or in your opinion receiving more than their fair share if water? Is the water supplying being compromised for local people whereas another group are not feeling the effects of the water crisis or is a pretty dire situation for everyone involved?

    Again, I found your case study really fascinating and i’m sure there so many more interesting things about it that you didn’t fit in the word count!
    Good Luck 🙂

    1. Dear Jan,

      Thank you so much for your comment. I am glad you enjoyed reading my blogpost! Your summary on the paradox, by the way, is spot on. It truly becomes a self-sustaining cycle.

      Also, I would be happy to address your questions. First, there is no formal governance or management structure for the Maipo watershed. Although, I must admit that I have not been able to find any more details on the “less than 1% under formal protection” figure, so I am afraid I cannot elaborate further on that. Second, you asked if there is a certain group benefiting most from water allocations. The situation of water rights in Chile is interesting because it is a wholly privatised system, where rights are traded in the market and therefore water is presented as a commodity. The main problem is that water rights are in the hands of large producers who have dried out certain territories. A popular protest chant in Chile, “it isn’t drought, it’s theft”, alludes to the idea that major industries like agriculture, hydro and mining have ‘stolen’ citizens’ water. Therefore, one can argue that there is concentration/inequality in the distribution of water rights which undermines a just development process and facilitates the economic exploitation of the environment. This kind of relates to your third question. Those who suffer the most are the citizens (who suffer from a shortage of drinking water) and the environment (which is contaminated with industrial waste).

      I hope I was able to sufficiently answer your questions. Let me know if you have any more!

  2. All the facts presented in the article are undoubtedly (and unfortunately) true, but I would suggest to put them into a proper perspective: just to mention (very briefly) that, somehow, all urban population of Santiago has excellent, universal and affordable drinking water supply, sewerage and wastewater treatment services. And also to try to explains why this happens in Santiago, but not in (most/all) other countries to the south of the United States, even those with similar level of economic development and those that have much more abundant water resources.

    1. Dear Andrei,

      Thank you so much for reading my blogpost and leaving a comment. I will absolutely take your suggestion under consideration when I write my final report. 🙂

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